18" rear wheel in ETZ251?

[dirtsurfer]

Hi
Sorry to but in. (First post , a bit rude I know) I am going to pick up an ETZ 250 project that has been sitting for a few years. Its missing a rear axel. Can someone tell me what size (diameter) the axel is so I can find something to fit for the time being when I pick it up




Edit Going by the wheel beating i/d . Im thinking its afraction under 15mm and I believe the length to be 230mm

[Eric Frith]

I'm fairly sure the rear bearing is a 6302 so dia is 15mm (going from memory, I could be wrong)

[Puffs]

So the bike has been rebuilt, imported & registered here (B), as an Oldtimer. For an Oldtimer the insurance is cheaper, but tax-wise it doesn't matter, as bikes below 250cc aren't taxed here.

I bought the bike in '98 in Scotland as I needed transport, and used it there for 7 years, and did a little over 20k miles on it. In Scotland it had already had a rebore, and a new crankshaft (small end failure), and I took it with me to Belgium as I liked particularly the engine. But I never used it here, it had been waiting for things to come for 12 years. But now, with the UK in their infinite wisdom having decided to leave the EU, I figured it was bound to become more difficult to import, so last winter I decided to start on the bike.

The abundance of salt had taken its toll, but with the frame down to bare metal it was actually fine. The fork gaiters had done their job, but both guide tubes had some pitting corrosion between the triple clamps, as did the rear springs. Of course the exhaust was worst of the lot; the black you can see on the muffler in my earlier pics (first post page 1, viewtopic.php?f=5&t=9127) was actually epoxy/glass fibre, to cover the holes. I decided to re-spray in the original blue, and from the colour of the inward part of the air box I could see the original colour; the outside, particularly the tank, had become considerably lighter. Very nicely made inlet tract, btw, with gravity separation in the frame, a quality paper filter & a proper airbox. Particularly for a 2T that's bound to help longevity & reliability.

Re-experiencing the bike, it's still a bit small for me, and the footrests are a bit too far forward for my taste, but it's the fastest of my old bikes (faster than a '76 Jawa 634 & a '80 SP400), and handles & steers well. It's a lively oldtimer (close to 80MPH, completely standard), eminently suitable for touring the country roads here in the Ardennes.

ETZ251 rebuilt, L.jpg (46.8 KiB) Viewed 47 times

ETZ251 rebuilt, R.jpg (46.19 KiB) Viewed 47 times

ETZ251 rebuilt, LF.jpg (48.78 KiB) Viewed 47 times

[dirtsurfer]

It looks fantastic. It has come up really well

[Puffs]

Thanks! Yes, it looks a lot better than before.

I've done a bit over 1000 miles with it by now, here in the Ardennes, after it not having run for almost 13years. No major issues, just that the brackets of the speedo & rev counter have both broken off once again. But I've been glueing those since about 2000.

Also interesting to note is the speedo. Being in Belgium, I had bought kilometre counter (that's 1 way to get a new bike - look, it's only done 1234 km!), but I found out that the gear ratio in the rear wheel hub is different for various versions. It looks like the mile version gets a different ratio than the km version? Anyway, with that counter & my gears I got silly speed (& distance) numbers. So back to the mile counter.

Time for a new rear tire, and I choose a 110/90-16. That is a bit bigger than the 3.5"x16" I used to run, both taller & wider. This is what it looks like:

110_90x16 in ETZ251.jpg (46.05 KiB) Viewed 47 times

Maybe next time I'll try a 120/90-60.

On flat ground it now has 10mm of clearance below the wheel, when on the centre stand, with a 120/90-60 that should be about 5mm. That might become a bit awkward on cobblestones or uneven grounds.

With this 110/90-16 I should get a -5mph error in top speed, and a -5.4% error in distance, compared to the standard 3.25"x16". Might need a smaller front sprocket too.